Various tamper-evident closures have been proposed wherein a threaded cap having a skirt portion provided with internal threads for connecting the cap to the threaded neck of a container. A ring is frangibly connected to the lower end of the cap skirt and is provided with a plurality of circumferentially spaced, inwardly and upwardly extending tabs or fingers integrally connected at their lower outer ends to the ring. The upper, inner ends of the tabs are adapted to engage beneath a shoulder or breaker ledge on the neck of the container located below the threaded portion thereof, whereby the cap is prevented from being removed from the container until twisted a sufficient distance to break the frangible connection, thereby separating the cap from the ring. These types of tamper-evident closures are disclosed U.S. Pat. Nos. 4,595,110, dated Jun. 17, 1986, and 4,807,771, dated Feb. 28, 1989.
Instead of molding the cap, frangible ring and tabs as an integral unit, it has been proposed to mold the tabs and frangible ring as an integral unit, which is then telescoped or pressed into or onto the skirt portion of the cap. These types of tamper-evident closures are disclosed in U.S. Pat. Nos. 4,493,427, dated Jan. 15, 1985, and 4,700,859, dated Oct. 20, 1987.
While these tamper-evident closures have been satisfactory for their intended purpose, they have been characterized by certain disadvantages in that the molded tabs are initially vertically oriented and have to be flexed into a semi-horizontal position toward the inside of the closure.
In the tamper-evident closures of the type wherein the integral unit of the frangible ring and tabs are pressed into or onto the skirt portion of the cap, there is a tendency for the integral unit to slip away from the cap before the frangible connection breaks, thereby defeating the tamper-evident feature of the closure.
After considerable research and experimentation, the tamper-evident closure of the present invention has been devised to overcome the disadvantages experienced with prior tamper-evident closures of the types noted above.